United Nations (CNN) -- It took decades to stamp out smoking inside the United Nations.
Now the U.N. may have another vice: drinking.
The United States ambassador for management and reform, Joseph Torsella, issued a rare public scolding, by U.N. standards, on personal behavior Monday.
He warned the U.N.'s "fifth committee" panel that negotiating rooms "should in the future be an inebriation-free zone."
U.S. diplomats say there has been excessive drinking surrounding traditional late-night meetings, especially during Christmas-time budget negotiations held by the fifth committee, which handles administration and budgetary matters.
No countries were formally named. However, Russian Ambassador Vitaly Churkin appeared to take some responsibility for his staff when he told CNN Wednesday "there should be no drinking during business sessions. And I'm going to give very clear instructions to that effect to my delegations."
Several other diplomats denied witnessing drinking during work hours. British Ambassador Mark Lyall Grant told CNN, "Of course in diplomacy there are a lot of receptions ... people may have a drink, but it's never come into negotiations."
The United Nations headquarters isn't exactly a frat house, but the combination of diplomats, staff, press corps and long hours can spark a relaxed atmosphere.
There used to be a bar inside a 'delegates lounge,' but because of building renovations in 2010, there are now few places to get a drink or eat after 3 p.m.
It appears some delegates are bringing liquor into the building.
A deputy spokesman for U.N. Secretary-General Ban Ki-moon, Eduardo Del Buey, said: "I don't think it's up to the secretary-general to tell the member states how to behave. It's up to the individual governments of the member states."
The most famous drinking story erupted overseas nearly three years ago when a senior U.N. official under Ban went on a drunken spiel aimed at his boss during a dinner.
He reportedly said "I know you never liked me, Mr. Secretary-General; well, I never liked you either." Sha Zukang, undersecretary-general for economic and social affairs, later apologized.
Torsella, who issued the drinking warning, has also been on the warpath against excessive business-class travel by U.N. staff who travel overseas.
He told his colleagues, "Let's save the champagne for toasting the successful end of the session and do some credit to the committee's reputation in the process."
Asked about drinking after the meetings, Churkin replied with a smile: "After is a private matter. We all have our private lives, don't we?"
CNN's Anna-Maja Rappard contributed to this report.